Add potential multi-dataset logger

[luismulinari]

Description

This PR adds a log entry containing the request information and backtrace when a potential multi-dataset query is detected.

Changelog Description

N/A

Pre-review checklist

• This change works and has been tested locally (or has an appropriate fallback).
• This change works and has been tested on a Go sandbox.
• This change has relevant unit tests (if applicable).
• This change uses a rollout method to ease with deployment (if applicable - especially for large scale actions that require writes).
• This change has relevant documentation additions / updates (if applicable).
• I've created a changelog description that aligns with the provided examples.

Pre-deploy checklist

• VIP staff: Ensure any alerts added/updated conform to internal standards (see internal documentation).

Steps to Test

1. Check out PR.
2. Perform a SQL query across multiple datasets
3. Observe logstash logs

[codecov]

Codecov Report

Merging #4920 (f75d518) into develop (280f1c3) will increase coverage by 0.10%.
The diff coverage is 94.44%.

@@              Coverage Diff              @@
##             develop    #4920      +/-   ##
=============================================
+ Coverage      29.12%   29.22%   +0.10%     
- Complexity      4744     4748       +4     
=============================================
  Files            278      278              
  Lines          20887    20905      +18     
=============================================
+ Hits            6083     6110      +27     
+ Misses         14804    14795       -9     

Files	Coverage Δ
...lass-potential-multi-dataset-queries-collector.php	90.19% <94.44%> (+2.31%)	⬆️

... and 7 files with indirect coverage changes

[mjangda]

Left some notes.

[mjangda]

😎